NEW YORK (Reuters Health) - Patients with multiple sclerosis (MS) with a history of smoking cigarettes had more destruction of brain tissue and more brain atrophy (wasting) than MS patients who never smoked, according to a study by researchers from the State University of New York, Buffalo.

In MS, the body's own immune system mistakenly attacks and damages its own myelin sheath, a fatty coating that protects nerve cells in the brain and spinal cord. MS can cause symptoms ranging from blurred vision, loss of balance, poor coordination and vague tingling to blindness and paralysis. There is no cure for the disease.

Cigarette smokers are at higher risk of developing MS, but the effect of smoking on the progression of the disease MS is uncertain.

Dr. Murali Ramanathan and colleagues analyzed brain scans of 240 MS patients who had never smoked cigarettes and 128 MS patients who were current or former cigarette smokers.

They found that "ever-smokers" had significantly more brain lesions -- patches of inflammation in the sheath surrounding the nerve fibers that impair their function -- and greater loss of brain volume and were more disabled than MS patients who had never smoked.

"Cigarette smoking is one of the most compelling environmental risk factors linked to the development and worsening of MS," Dr. Robert Zivadinov who was involved in the study added in a university-issued statement.

"Such direct evidence may resonate more strongly with multiple sclerosis patients and physicians could provide the information and encourage patients to quit smoking," Ramanathan noted in an email to Reuters Health.